The Korean War highlighted the war against communism to the minds of US Citizens, e.g. the slogan(s) "...Better Dead than Red..." etc.
Very few of the former Mexican Citizens chose to move south. Most opted to remain where they were for one year and automatically become US Citizens. The impact on the Mexican American War population is that they are huge today in California, Arizona New Mexico. Nevada, Utah and Colarado. In these areas the population grew very large after the Mexican American War.
The Korean war had a very profound impact on the US. It cost a little over two billion dollars in supplies for the troops and it cost 54,291 in American lives. General Douglas MacArthur was a household name at the peak of the Korean war because of his services in WWII but when he was removed from the US army by Truman for attempting to wage all out war on North Korea and the Soviet Union, many people in the US and even the UK were outraged.